I fully agree with the information in this artica, BUTT I will add one thing regarding hemlet venting: I came home to west coast after completing the extreme fourcorners ride in May and June, It was Mid june when I left Florida west coast, mostly rain that day to Sidell LA. next day to Houstin and it wa hot! a two day break there seeing friends, then a day ride to Austin and two more days , more friends, then a major rideday from Austin TX to Deming NM. Once the day heaed up it was hot, I had plentyof water and used it so no problem, Next day same hot weather and made it to Mohave CA, I noticed tha evening that the top of my head felt quite warm; when I took off hemlet all seemed ok, after a shower I happened to look in mirror; MY nearly bald top of my head had a long RED mark from front to back. I initialy thought wa what is this?? then it dawned on meI had ran with the AIR vents in my Schulberth concept open all day long on both days, I was usinga Silks hemlet liner tha I would wash out each niteBUT the wind entering te top of the hemlet had BURNED me real gooddurring the two long hot days , This was on the GL 1800 with very good wind protection. My advice is to NOT RIDE LONG MILES / HOURS WITH HEMLET VENTS OPEN, it took quite awhle for me to recover from those burns and I still remember them very well.
Smaller windshield??
- Thread starter Builtdesign
- Start date
I've got LD Comfort's helmet liner and wear it on real hot days. I wet it every time I stopped when I spent four days riding in Texas in temps above 100 last June. 'Course, I got hair... 
Well, you live near the hottest state I've ever ridden in. Central Washington is just plain hot. I think it got up to about 108 or so the day four of us were riding to Centralia for the COG Rally in '05. We sat at a gas station in Othello and just kept drinking water. That was before I had the LD Comfort stuff.
I went back and reread my post.
I was not in any way trying to mislead or misinform anyone or intentionally give out false information with my comments or cause any safety issues for anyone. My sole intention was to say the evaporative cooling effect does not work as well here in the humid south and that was all. Period.
I was not in any way trying to mislead or misinform anyone or intentionally give out false information with my comments or cause any safety issues for anyone. My sole intention was to say the evaporative cooling effect does not work as well here in the humid south and that was all. Period.
Good for you, failing on the safe side of heat exhaustion or heat stroke is better than tempting it. And that evaporative cooling only works at speed. Some stop and go traffic will set you back and now you will be overheating again.
That iron butt article does a great job of illustrating heat transfer. Heat Transfer and Fluid Flow are not the most exciting topics but it helps to have an understanding for several aspects in life. I may have skipped over it, but it is helpful to know that everyones ability to dissipate heat is different. Several factors change from one to the next including age, weight, health (heart ), probably others. As we get older our "thermostat" may not work as good as it did when we were younger. You also need to be able to get the hot blood near the surface/skin for the heat to be removed. Drug and alcohol can change that too. Some have better blood flow near the skin and can cool better.
I only remember riding once at >95f and I soaked a thermal underwear shirt (thick and holds a lot of water) in water, covered with riding jacket, closed all vents and was laughing at how cold I was getting. It took almost 3 hours to dry out and start getting hot again.
So, to be exact about it, evaporative cooling "works" until you reach 100% relative humidity. It works less well as you go from 0-100% (yes, I am a mechanical engineer and I used to teach this stuff ).
If the outside temp is 50F and RH of 100% there is no evap cooling. If the RH is 99% there will be cooling but very little, no matter what the temp.
One more point is the sun. Direct sunlight will do as much to kill you as anything else. The military uses the Wet Bulb Globe Temperature (WBGT) for that reason.
'Listen' to your body. If it feels like you are getting hotter, you are!
).If the outside temp is 50F and RH of 100% there is no evap cooling. If the RH is 99% there will be cooling but very little, no matter what the temp.
One more point is the sun. Direct sunlight will do as much to kill you as anything else. The military uses the Wet Bulb Globe Temperature (WBGT) for that reason.
'Listen' to your body. If it feels like you are getting hotter, you are!
Thank you for the quick "Cliff Notes" class...it was a good way to explain it.
The relative humidity in Hotlanta is one of my biggest problems...add in stop and go traffic, heated exhaust fumes, and it is a real problem.
Mellow
Admin
Yeah, one reason the phase change vest work so great is humidity is taken out of the equation... I had one of those vests and would commute to/from work in TX 100 degree heat and believe it or not, I wasn't sweating like a pig by the time I rode 20 miles home.
The problem with them is they do add about 1" front and back inside your gear so it makes you feel like you're wearing a life jacket inside your jacket but you get home and your dress shirt isn't soaking wet. I did find it was okay by just using the packs in the front of the vest and not the back.
Using them on a trip gets to be difficult as well because you have to figure out how to recharge them with water/ice. They would generally last pretty long but in the end I sold it because I wasn't commuting anymore and I didn't ride in hot enough conditions for long periods to justify dealing w/extra bulk the rest of the trip when not in use.
The problem with them is they do add about 1" front and back inside your gear so it makes you feel like you're wearing a life jacket inside your jacket but you get home and your dress shirt isn't soaking wet. I did find it was okay by just using the packs in the front of the vest and not the back.
Using them on a trip gets to be difficult as well because you have to figure out how to recharge them with water/ice. They would generally last pretty long but in the end I sold it because I wasn't commuting anymore and I didn't ride in hot enough conditions for long periods to justify dealing w/extra bulk the rest of the trip when not in use.